BQ3285S-SB2TR Equivalent & Substitute Parts

Part Overview

The BQ3285S-SB2TR is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Texas Instruments. This device provides 114 bytes of parallel-accessible memory with alarm, daylight savings, leap year, and non-volatile static RAM (NVSRAM) capabilities. The part is classified as obsolete, making equivalent and substitute components necessary for new designs and ongoing production support.

Key Parameters

Parameter	Value
Part Number	BQ3285S-SB2TR
Manufacturer	Texas Instruments
Category	Clock/Timing
Product Status	Obsolete
Package Type	24-SOIC (0.295", 7.50mm Width)
Memory Size	114B
Interface	Parallel
Supply Voltage	4.5V ~ 5.5V
Battery Voltage	2.5V ~ 4V
Operating Temperature	0°C ~ 70°C
Time Format	HH:MM:SS (12/24 hr)
Date Format	YY-MM-DD-dd
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution for the BQ3285S-SB2TR is determined by the following critical parameters:

Direct Electrical Compatibility (Same Package, Same Voltage, Same Temperature Range):

Package: 24-SOIC form factor
Supply voltage: 4.5V ~ 5.5V
Battery voltage: 2.5V ~ 4V
Operating temperature: 0°C ~ 70°C
Memory size: 114B
Interface: Parallel
Time/Date format: HH:MM:SS (12/24 hr) and YY-MM-DD-dd

Upgrade Compatibility (Enhanced Features, Extended Temperature, Same Package):

Package: 24-SOIC form factor
Supply voltage: 4.5V ~ 5.5V
Operating temperature: -40°C ~ 85°C (extended range)
Memory size: 114B
Interface: Parallel
Additional features: Trickle-charger capability

Manufacturer Recommended Alternatives (Different Package, Different Voltage, Enhanced Functionality):

Alternative packages: 28-SOIC, 32-DIP Module, 28-DIP Module, 24-DIP Module
Alternative supply voltages: 3V ~ 3.6V, 2.97V ~ 3.63V, 2.7V ~ 3.7V
Enhanced memory: 256B, 32KB
Extended temperature ranges: -40°C ~ 85°C
Additional features: Watchdog timer, Y2K compliance

Parameter Comparison

Part Number	Manufacturer	Package	Memory	Supply Voltage	Battery Voltage	Operating Temp	Status	Timekeeping Current
BQ3285S-SB2TR	Texas Instruments	24-SOIC	114B	4.5V ~ 5.5V	2.5V ~ 4V	0°C ~ 70°C	Obsolete	—
DS12885S+	Analog Devices Inc./Maxim Integrated	24-SOIC	114B	4.5V ~ 5.5V	2.5V ~ 4V	0°C ~ 70°C	Active	15mA @ 4.5V ~ 5.5V
DS12885S+T&R	Analog Devices Inc./Maxim Integrated	24-SOIC	114B	4.5V ~ 5.5V	2.5V ~ 4V	0°C ~ 70°C	Active	15mA @ 4.5V ~ 5.5V
DS12885SN+	Analog Devices Inc./Maxim Integrated	24-SOIC	114B	4.5V ~ 5.5V	2.5V ~ 4V	-40°C ~ 85°C	Active	15mA @ 4.5V ~ 5.5V
DS12R885S-5+	Analog Devices Inc./Maxim Integrated	24-SOIC	114B	4.5V ~ 5.5V	2V ~ 3.05V	-40°C ~ 85°C	Active	2mA @ 4.5V ~ 5.5V
DS12R885S-5+T&R	Analog Devices Inc./Maxim Integrated	24-SOIC	114B	4.5V ~ 5.5V	2V ~ 3.05V	-40°C ~ 85°C	Active	2mA @ 4.5V ~ 5.5V
DS1501WZN+	Analog Devices Inc./Maxim Integrated	28-SOIC	256B	3V ~ 3.6V	2.5V ~ 3.7V	-40°C ~ 85°C	Active	4mA @ 3V ~ 3.6V
DS1501WZN+T&R	Analog Devices Inc./Maxim Integrated	28-SOIC	256B	3V ~ 3.6V	2.5V ~ 3.7V	-40°C ~ 85°C	Active	4mA @ 3V ~ 3.6V
DS1554W-120IND+	Analog Devices Inc./Maxim Integrated	32-DIP Module	32KB	2.97V ~ 3.63V	—	-40°C ~ 85°C	Active	4mA @ 3.3V
DS1687-3+	Analog Devices Inc./Maxim Integrated	24-DIP Module	242B	2.7V ~ 3.7V	2.5V ~ 3.7V	0°C ~ 70°C	Active	2mA @ 3V
DS1744-70IND+	Analog Devices Inc./Maxim Integrated	28-DIP Module	32KB	4.5V ~ 5.5V	—	-40°C ~ 85°C	Active	4mA @ 5V

Engineering Selection Recommendations

For Direct Pin-Compatible Replacement (24-SOIC, 4.5V ~ 5.5V Supply):

DS12885S+ and DS12885S+T&R are direct electrical equivalents with identical package, voltage, and temperature specifications. Both are active products with full RoHS3 compliance. The primary difference is packaging format: DS12885S+ is supplied in tube packaging, while DS12885S+T&R is supplied in tape and reel format. Selection depends on assembly process requirements.

For Extended Temperature Range Applications (-40°C ~ 85°C):

DS12885SN+, DS12R885S-5+, and DS12R885S-5+T&R extend the operating temperature range while maintaining the 24-SOIC package and 4.5V ~ 5.5V supply voltage. DS12R885S-5+ variants include trickle-charger functionality and operate with reduced battery voltage (2V ~ 3.05V) and lower timekeeping current (2mA), making them suitable for extended battery-backed operation.

For Low-Voltage Applications (3V ~ 3.6V Supply):

DS1501WZN+ and DS1501WZN+T&R operate at 3V ~ 3.6V supply voltage with 28-SOIC packaging and 256B memory. These are active products with extended temperature range (-40°C ~ 85°C) and full compliance certifications.

For Through-Hole Mounting Applications:

DS1554W-120IND+ (32-DIP Module, 32KB memory) and DS1744-70IND+ (28-DIP Module, 32KB memory) provide through-hole alternatives with significantly larger memory capacity. DS1687-3+ (24-DIP Module, 242B memory) maintains similar memory size to the original part while offering through-hole mounting.

All substitute parts maintain RoHS3 compliance and REACH unaffected status consistent with the original BQ3285S-SB2TR.

Frequently Asked Questions (FAQ)

Q: Can DS12885S+ directly replace BQ3285S-SB2TR without circuit modification?

A: Yes. DS12885S+ is electrically and mechanically compatible with identical package (24-SOIC), supply voltage (4.5V ~ 5.5V), battery voltage (2.5V ~ 4V), memory size (114B), and operating temperature range (0°C ~ 70°C). No circuit modifications are required.

Q: What is the difference between DS12885S+ and DS12885S+T&R?

A: Both parts are electrically identical. The difference is packaging format: DS12885S+ is supplied in tube packaging for manual assembly, while DS12885S+T&R is supplied in tape and reel format for automated pick-and-place assembly.

Q: Why would I choose DS12R885S-5+ over DS12885S+?

A: DS12R885S-5+ offers extended operating temperature range (-40°C ~ 85°C), lower timekeeping current (2mA versus 15mA), reduced battery voltage requirement (2V ~ 3.05V), and integrated trickle-charger functionality. These features are beneficial for industrial applications and extended battery-backed operation.

Q: Are the DS1501WZN+ and DS1744-70IND+ pin-compatible with BQ3285S-SB2TR?

A: No. DS1501WZN+ uses 28-SOIC packaging and DS1744-70IND+ uses 28-DIP Module packaging, both different from the original 24-SOIC package. These are manufacturer-recommended alternatives for new designs requiring enhanced memory or different mounting technologies, not direct replacements.

Q: What is the memory difference between BQ3285S-SB2TR and the recommended alternatives?

A: BQ3285S-SB2TR provides 114B of NVSRAM. DS1501WZN+ provides 256B, DS1554W-120IND+ provides 32KB, and DS1744-70IND+ provides 32KB. DS1687-3+ provides 242B. Memory selection depends on application requirements for non-volatile storage capacity.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts maintain RoHS3 compliance and REACH unaffected status consistent with the original BQ3285S-SB2TR.

Q: What mounting type should I select for surface mount applications?

A: For surface mount, select from 24-SOIC or 28-SOIC packages: DS12885S+, DS12885S+T&R, DS12885SN+, DS12R885S-5+, DS12R885S-5+T&R, DS1501WZN+, or DS1501WZN+T&R. For through-hole mounting, select from DIP Module packages: DS1554W-120IND+, DS1687-3+, or DS1744-70IND+.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message